变极距电容位移传感器的双频激励方法研究  

Dual-frequency excitation for variable gap capacitive displacement transducer

作　　者：张立锋[1] 俞红祥[1] 沈孟锋[1] 

机构地区：[1]浙江师范大学运动检测与智能控制研究中心,浙江金华321004

出　　处：《电子元件与材料》2015年第4期26-31,共6页Electronic Components And Materials

基　　金：国家自然科学基金项目资助(No.51105343);浙江省青年科学基金项目资助(No.LQ12E05004);浙江省新苗人才计划资助(No.2014R404081)

摘　　要：针对变极距电容位移传感器提出了一种双频激励方法。同时采用低频、高频正弦电压源激励平板发射电极,通过电容耦合效应将极距变化转换为双频调幅信号,并通过高阻抗缓冲、带通滤波、精密整流电路获得双路位移调制电压信号。采用数字信号处理器(DSP)同步采集双路位移调制电压信号以及参考位移信号,对高、低频激励方式下的位移检测分辨率、纹波、动态响应速度等性能进行了对比分析。实验结果表明:双频激励时,通道间耦合作用较小,低频激励方式在位移分辨率、测量范围、线性度、抗干扰等指标上显著优于高频激励;高频激励在动态响应速度上具有明显优势。A dual-frequency excitation method was proposed for variable gap capacitive displacement sensor, in which, the stator was driven by a couple of sinusoidal voltage signals with low and high frequency. Through capacitance coupling and modulation circuit, a relative displacement between stator and mover of the transducer was converted to dual sync displacement-modulated voltage signals. The displacement detection resolution, static ripples and dynamic response were acquired and analyzed using digital signal processor（DSP）. The obtained data indicates that dual-frequency excitation emerges very low inter-channel coupling interference, and the low frequency excitation shows significant superior in displacement resolution, measuring range, linearity and anti-interference performance while the high frequency excitation has obvious advantages in dynamic response.

关 键 词：双频激励 电容传感器 位移测量 振动检测 调制信号 DSP 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]